ENCON - Thermal Evaporators
ENCON Thermal Evaporators are a time-tested method for economically reducing the water portion of water-based wastes. It is our most flexible system in terms of heat sources available and the different ways to configure the system including batch, semi-batch, and continuous operation as well as options to recover steam as distilled water. ENCON Thermal Evaporator Systems are available in a wide range of standard capacities, from 8 to 400 gallons per hour and heat sources that include: gas, propane, electric, steam, oil, waste oil, off spec gas, and waste heat. ENCON was founded more than 20 years ago with the Thermal Evaporator offering and that original system has evolved and been improved upon to the point it is today which is the industry leader with widest range of configurations.
What Does a Thermal Evaporator System Do?
Put simply, the ENCON Thermal Evaporator Systems allows you to efficiently and affordably convert the water-based portion of water-based wastes to water vapor, while leaving the higher boiling contaminants behind. This can eliminate the need to discharge wastewater to the sewer and or greatly minimizes the amount of waste that needs to be hauled off-site.
If your waste stream is substantially water (70-99%), it is likely to be an excellent application for ENCON wastewater evaporators.
The blower system consists of a 1725 RPM, TEFC, motor with Class-B insulation rated for high temperatures and a heavy gauge cast aluminum blower for durability and longevity. The blower system is extremely quiet and has 3 times the average life expectancy of 3450 RPM motors. Thermal overload protection is included on the blower motor.
Forced Draft Burner
Each fuel heated system consists of a burner with: Honeywell controls; pressure gauge and gas volume meter for monitoring gas inlet conditions; airflow detection and lockout; spark ignition; redundant main valve and burner contactors for maximum safety. FM gas trains and gas flow transmitters are standard on larger systems. The stainless steel burner protection shroud is mounted on a track hanger for ease of removal and reattachment. Natural gas, Propane, Dual Fuel, Oil, Diesel, Waste Oil and Low NOX burners are available.
Redundant Burner Contactors
To ensure maximum safety, each burner-fired unit comes with redundant contactors. This critical safety feature ensures the burners will shut down in the event of an alarm condition. If an alarm condition occurs that requires the burners to shut off and the primary duty burner contactor becomes mechanically stuck, the redundant burner contactor will open to ensure system shutdown.
Our durable tuning fork level probes operate through a piezoelectric crystal that creates a frequency shift as conditions around the probe change. These probes are fabricated of a stainless/titanium alloy for excellent corrosion resistance. Tuning forks offer reliable auto-filling and fail safe shut-down operation. This reliability is complimented by the ongoing diagnostics performed on the level probes by the PLC control system. Optional Hastelloy C probes are available for more corrosive applications.
Mist Eliminator System
Over the years, competitive evaporators have been known to discharge unwanted contaminants through their exhaust stack.The ENCON Wastewater Evaporator is designed with a fabricated stainless steel housing and mist eliminator to capture contaminants before they are exhausted. Our effective mist capturing system has the following features for proper functionality:
- Compression fit mist pad to capture unwanted contaminants before exhausting.
- Ease of removal and cleaning to minimize manpower requirement.
- An adequate buffer zone between the water level and the mist pad, to allow fall back of contaminants.
- Adequate mist pad surface area to regulate vapor velocity and prevent blow through of contaminants.
- Monitoring of mist pad loading to ensure consistent evaporation rate.
- Mist pads rated from 2 - 10 microns to capture even the smallest droplets.
Integrated Control & Monitoring System
ENCON Wastewater Evaporators (excluding the Drum Evaporator) are controlled with Programmable Logic Controllers (PLC's). The PLC control and monitoring logic is designed for optimal safety and operator feedback.
Features of this system include:
- NEMA 4 Panel with modem to allow remote access by ENCON Engineers for monitoring and troubleshooting.
- Operator Interface Panel with scrolling text messages for normal and alarm conditions.
- Continuous monitoring of mist pad pressure, air temperature, and water temperature.
- Continuous level probe diagnostics.
- Alarm indications for high temperature, high level, low level, mist pad differential pressure, and level probe malfunction.
- Indicator lights for main power, burner(s), and alarms.
- Keypad for setpoint display and modification with lockout feature.
The ENCON Wastewater Evaporator has a large six inch flanged cleanout cover with a 1 ½' NPT fitting for discharge pump connection and ease of residue removal (8 and 10 gal/hr units have a four inch flanged cleanout cover with a 1' NPT fitting). The tank bottom slopes towards the cleanout, making tank cleaning an efficient task compared to our competitor's 2' or 4' opening.
Available Capacities and Heat Sources for ENCON Thermal Evaporators
Encon offers a number of different heat sources options for our thermal evaporator line. This allows you to select the most cost effective option for your individual needs.
Thermal Evaporators are available in capacities ranging from 8 gallons per hour up to 400 gallons per hour. Please reference the chart below to see what sizes are available for your preferred heat source.
Material Of Construction
All ENCON Thermal Evaporators are clad with 304 stainless steel exterior for long term corrosion resistance. The standard material of construction for the tank and heat exchanger (the parts of the evaporator that come in contact with the wastewater) are manufactured from 316L stainless steel. This provides excellent corrosion resistance for many types wastewaters. Unlike others, ENCON does not use 304 stainless steel on wetted parts of the evaporator and charge extra for 316.
NEMA 4 PLC control panel with touch screen OIT provides readout of wastewater and heated air temperatures along with alarm and operating conditions for maximum operator feedback. Built-in cycle timer and Ethernet port.
Standard on: Thermal units 72gph or smaller heated by natural gas, propane, kerosene, electricity or off-spec landfill gas.
Has all the functionality of the standard V1 control logic with the addition of analog output and Auto-Decant capabilities.
Standard on: oil, diesel, and waste oil powered thermal evaporators, thermal evaporators with the auto-decant option and all thermal evaporators 96gph and above.
Larger touch screen interface with graphical display and the ability to view data logs on the control screen.
Allen Bradley PLC
Sampling of available accessories to increase the functionality of the ENCON Thermal Evaporator.
Digital Combustion Analysis Kit
Digital combustion flue gas analyzer. Capable of providing readings on CO, CO2, O2, pressure and temperature of flue gases. Includes analyzer, sampling probe, filter/water trap, battery charger and carrying case.
HDPE Cone Bottom Holding Tank w/ Stand
HDPE Cone Bottom Holding Tank with Integrated Stand. Available from 175 - 2,500 gallon capacity.
Feed Pumps are designed to transfer the wastewater from a holding tank/sump to the evaporator.
Residue pumps are designed to transfer the residue to a holding tank/sump from the evaporator.
Condenser w/ Condensate Sump
This upgrade is designed to condense the evaporated water vapor and send it to a tank within 20 feet of the evaporator for re-use. This upgrade includes upgraded PLC and programming, draft inducer, condenser and automatic condensate sump. Cooling water is required.
Auto-Dump / Auto-Restart
This upgrade is designed to automate the emptying of the evaporator to a customer supplied residue holding tank and to allow the evaporator to restart upon completion. This option includes evaporator tank empty level probe, electrically actuated ball valve on the evaporator outlet and a high temperature level probe for the residue holding tank.
Auto-Decant / Auto-Restart
This upgrade is designed to automate the decanting of the floating oil layer in the evaporator to a customer supplied oil holding tank and to allow the evaporator to restart upon completion. This option includes an upgraded PLC and programming, water/oil sensing probe, electrically actuated ball valve on the evaporator oil decant outlet and a high temperature level probe for the oil holding tank.
The following is a summary of the ENCON Thermal Wastewater Evaporator Models and their respective dimensions.
- The dimensions for the 8 gph electric unit are equivalent to this unit except it is 12' shorter in length.
- The dimensions for the 15 gph electric unit are equivalent to this unit except it is 12' shorter in length.
- The dimensions for the 24 gph electric unit are equivalent to this unit except it is 12' shorter in length.
- The dimensions for the 40 gph electric unit are equivalent to this unit except it is 12' shorter in length
Evaporation and Distillation Mode
- Wastewater is collected in a holding tank, sump, or pit and is either pumped or gravity fed into the wastewater evaporator through a 1' NPT fitting on the lid.
- The three (3) level probes in the standard auto-fill system provide:
- Low Level (LL) provides on/off control for the heat source.
- Auto Level (AL), along with timer based control function from the PLC, initiates and stops the fill sequence.
- High Level (HL) is a redundant safety for the auto level (AL).
- Fluid will continue to flow until it reaches the high-auto level probe. At this point, the feed sequence will stop.
- As the fluid comes to a boil and the evaporation process begins, the liquid level will drop down to the low-auto level probe. The feed sequence will activate and more fluid will be fed into the wastewater evaporator until the level reaches the high-auto level probe.
- The wastewater evaporator system will continue to cycle in this manner until either the fluid temperature controller reaches the high set point, the cycle timer counts down to zero, or there is no longer wastewater to be fed to the evaporator.
Distillation Mode Only
- The hot water vapor created inside the evaporator is drawn through the mist eliminator by the exhaust blower and pushed through the shell and tube condenser. The water vapor is condensed and then captured as high quality distilled water in the sump located directly below the condenser support shelf.
- The dehumidified air passes through another mist eliminator and is returned for recirculation through the evaporator tank.
Distillation Flow Diagrams/Descriptions by Heat Source
Distillation Flow Diagram with Gas / Propane / Oil Heat Source
Distillation Flow Diagram with Steam Heat Source
Distillation Flow Diagram with Electric Heat Source
Evaporation and Distillation Mode
Installation of the ENCON Thermal Industrial Wastewater Evaporator is very straight forward and is generally handled by facilities, maintenance or plant engineering personnel. Primary connections include plumbing from the holding tank, sump, or pit to the feed pump and/or inlet valve. Then from the pump and/or inlet valve to the 1' NPT inlet located on the lid of the evaporator. Other optional plumbing includes hard piping with a manual ball valve from the fitting on the residue cleanout flange to a residue holding tank as well as providing a nipple and manual ball valve to allow for decanting of free oil to a drum.
Stacks of varying materials (galvanized, stainless, or CPVC) are easily fitted over the blower exhaust outlet. The stack is typically installed vertically through the ceiling but can also be run at an angle to a nearby wall then run vertically up the side of the building.
Finally, electrical power is run to the auxiliary control panel on the rear of the evaporator. Single phase, 110 VAC power is required for units 8-72 gal/hr (excluding electrically heated systems which require either 240 or 480 VAC, three phase power) and three phase, 240 or 480 VAC power is required for units rated 96-400 gal/hr. All primary system components such as level probes, blowers, burners, and modem are prewired and tested at the factory.
Below is a typical layout of an ENCON Thermal Industrial Wastewater Evaporator.
The only stack required for the ENCON Distillation System is for the flue gas. A high temperature (350-550F flue gas) B-Vent stack can be easily fitted over the outlet end of the draft inducer located on the chimney side of the system. The stack is typically installed vertically through the ceiling but can also be run at an angle to a nearby wall then run vertically up the side of the building. Electrical requirements are the same as for the Thermal Evaporator systems operating in evaporation mode: